1. Field of the Invention
The present invention relates generally to electronic communication and more particularly, to a communication system and a communication method for near field communication (NFC).
2. Description of the Related Art
NFC is a new short-distance wireless connection technique, allowing electronic apparatuses to do contactless point-to-point data transmission between or among them. For recent years, the communication technology regarding mobile devices has been boomed and the mobile devices having built-in NFC can simplify the conventional shopping to help the people go on-line, receive, and share information more quickly and complete payment and transaction.
The application of NFC of a mobile device is primarily based on the interaction between the NFC reader and the security module of the mobile device. The security module of the mobile device can be a subscriber identity module (SIM) card, a microSD card, or an embedded security module. Most of commercially available mobile devices supporting NFC are of physical circuits based on single wire protocol (SWP) for guiding NFC signals to the SIM card of the mobile device for processing. However, it is difficult to apply such architecture to the cash flow of NFC-enabled transaction in practice. For example, if it is intended for a mobile phone to process NFC signals by means of a microSD card, it will be necessary to guide the NFC signal signals to the microSD card from the SIM card through a conducting wire, so it is very inconvenient in operation.
Among the state-of-the-art technology in this field, host card emulation (HCE) has been adopted by some manufacturers, providing ISO14443 and ISO 7816 standards for NFC and allowing software developers to devote themselves to development of software security modules without concern about the NFC-enabled communication.
HCE brings many different applications for NFC-enabled transactions from those of the conventional ones. Cash-flow vendors attempt to make applets existing in smart cards tokenized in clouds or mobile devices and make the tokenized applets interact with NFC readers by HCE. Such new NFC transaction method may though have the advantage of quick deployment, but the mobiles devices serving as cryptographic operation and token storage lead to a very high security risk, so such method has still been unprevalent.
Referring to FIG. 1, a mobile device 1 having an HCE system 10 installed therein includes an HCE application program 101 and an NFC controller 102. The mobile device 1 further includes a security module 103, which can reach the NFC controller 102 by means of SWP. When an external NFC reader 2 emits a signal S and the signal S is received by the mobile device 1, the NFC controller 102 can provide two paths for NFC. In the first path, a signal S reaches the NFC controller 102 via a path 21 and then the NFC controller 102 transmits the signal S to the HCE application program 101 via a path 22; the HCE system 10 is used for emulating an applet of the security module 103 for the purpose of NFC transaction. In the second path, the signal S reaches the NFC controller 102 via the path 21 and the NFC controller 102 transmits the signal S to the security module 103 via a path 23 by means of SWP. Thus, the second path is still the conventional physical circuit. The NFC controller 102 maintains an application ID routing table (not shown) for confirming the destination of the signal S. If the NFC controller 102 is provided with an applet ID (AID) of the security module 103, the NFC controller 102 will transmit the signal S to the second path; otherwise, the NFC controller 102 will transmit the signal S to the first path.
When the HCE system 10 carries out NFC via the first path, the signal S can be processed directly by the HCE application program 101. When the HCE system 10 carries out NFC via the second path, the signal S will be processed by the security module 103.
Although the HCE system 10 comes up with the simple software emulation to slash the threshold of development of NFC, however, the HCE application program 101 is devoid of secure storage that is available in the conventional security module 103, so some important keys (not shown) must be stored in software format to lead to security concern. Besides, the conventional SWP-based path 23 using the security module 103 (e.g. SIM card) for carrying out NFC is incompatible with the payment system of the existing banks serving as the primary cash flow.
In light of the above, an NFC-based communication system using the HCE technology for guiding NFC signals to the security module (e.g. microSD card) is needed for preventing the NFC signals from hardware limitation to SWP and avoiding the aforesaid drawback of the software emulation.